English

Orientations making k-cycles cyclic

Combinatorics 2015-02-25 v1

Abstract

We show that the minimum number of orientations of the edges of the n-vertex complete graph having the property that every triangle is made cyclic in at least one of them is log2(n1)\lceil\log_2(n-1)\rceil. More generally, we also determine the minimum number of orientations of KnK_n such that at least one of them orients some specific kk-cycles cyclically on every kk-element subset of the vertex set. The questions answered by these results were motivated by an analogous problem of Vera T. S\'os concerning triangles and 33-edge-colorings. Some variants of the problem are also considered.

Keywords

Cite

@article{arxiv.1502.06888,
  title  = {Orientations making k-cycles cyclic},
  author = {Zita Helle and Gábor Simonyi},
  journal= {arXiv preprint arXiv:1502.06888},
  year   = {2015}
}

Comments

9 pages

R2 v1 2026-06-22T08:36:48.821Z